Passwordless is an Elixir library for generating and redeeming one-time tokens.

These tokens can be used as a layer in a Multi-Factor Authentication (MFA) scenario or in place of user passwords in a Single-Factor Authentication (SFA) scenario. See: 360 million reasons to destroy all passwords.

1. Add passwordless to your list of dependencies in mix.exs:

```elixir
defp deps, do: [{:passwordless, "~> 0.1.0"}]
```

2. Ensure passwordless is started before your application:

```elixir
def application, do: [applications: [:passwordless]]
```

defp send_token(user) do
  user.id
  |> Passwordless.generate_login_token()
  |> email_login_link(user)
end

defp create_session(token) do
  case Passwordless.redeem(token) do
    {:ok, user_id} -> MyApp.log_in(user_id)
    :error -> MyApp.handle_expired_token(token)
  end
end